Oil combustion apparatus



y 1936- o. c. SCHROEDER ET AL 2,@39,936

OIL COMBUSTION APPARATUS 3 Sheets-Sheet 1 Filed Jan. so, 1935 .[fiven07.19.- Oscar C. osckroeder,

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y 1936- o. c. SCHROEDER ET AL 6 OIL COMBUSTI ON APPARATUS Filed Jan. 50,1955 3 Sheets-Sheet 5 Patented May 5, 1936 UNITED STAT PATENT OFFICE OILCOMBUSTION APPARATUS Illinois Application January- 30, 1933, Serial No.654,356

20 Claims.

Our primary object is to provide an oil-combustion apparatus of the typein which the combustion of the oil delivered from the center of thehearth takes place generally in the form of a ring at the outerperipheral por ion of the hearth, improvements to the end that completecombustion of the fuel will be elfected and maximum .efficiencyobtained.

More specific objects are to provide a hearth of such construction andassociate therewith .3 burner in such a way, that the result above re.-ferred to may be effected; to provide, in a-structure of the characterabove referred to and embodying gas-ignition means, for the shielding ofthe gas flame from the direct blast produced by the burner, withoutimpairing its usefulness for igniting the fuel; to provide for thethorough intermixing of the oil, in vaporized condition, and the air toeffect complete combustion relatively close to the hearth; to provide aconstruction whereby leakage of air through the hearth will beprevented; and other objects as will be clear from the followingdescription.

Referring to the accompanying drawings:

Figure 1 is a view in elevation of a furnace embodying our inventionyandcomprising, as an element thereof, an oil-burner assembly certain partsof the structure shown being represented in sectional elevation.

Figure 2 is an enlarged broken sectional view in elevation of theignition means for the burner and a portion of the furnace hearth, thesection being taken at the line 22 on Fig. 3, and viewed in thedirection of the arrow.

Figure 3 is a broken plan view of the portion of the hearth shown inFig. 12 showing the pilots in plan section.

Figure 4 is a developed view in elevation of the portion of the hearthshown in Fig. ,3, the hearth being viewed from the interior ofthefurnace and the view being taken along the line';4-,4 on Fig.

3 and viewed in the direction of the-arrows.

Fig. 5 is a plan View of my improved hearth ring sections of such shape,,number ,and grouping as to form a hearth ring of one diameter; and

Fig. 6, a similar view of the hearth ring sections of such numberandigrouping as to form a ring of a larger diameter.

Referring to the particular construction shown, 9;,represents-a furnace,shown as of the hot-water boiler type, having a combustion chamber Iformed with a hearth portion of refractory ma terial centrally aperturedand supported on a centrally apertured plate II, as forrexample' ofmetal, carried by the base I2 of thefurnac'ei The hearth portion shownformed of any suitable refractory material comprises a ring-like baseportion I3 having at its outer periphery an upwardly extending ring-likeside-wall forming flange III, a ring I superposed on the ring portion I3concentrically therewith but of smaller diameter, and a ring I6preferably formed of arcu ate sections disposed ina circular series andresting on the outer marginal portion of the ring I3 beyond the ring I5and filling the space between the. ring I5 and the lower end portion ofthe sidewallforming flange M.

It may here be said that in the assembling of the parts of thecombustion apparatus the oil burner assembly is positioned at the lowerend 1;

of the combustion chamber I0, and the plate II then applied in theposition shown. The base portion I3 preferably formed of cement is then,cast on the plate, and, if desired, the flange portion I4 castseparately, in which case the one portion last to be cast is cast beforethe other sets. Thus in eithercase the base with its flange formamonolithic structure free of joints. After applying to place thesections of the hearth ring I6 cement to form the ring I5 is cast on thebase portion I3.

The ring It comprises an annular base portion H the inner peripheryof-which is of stepped form to provide, at a considerable distance belowts upper edge I8, an annular oil-receiving trough,.orgroove, I9 and alower inwardly located annular recess 2|] presenting anannularshoulder-forming'wall ZI, The hearth-ring I6 also comprises concentricannular inner and outer series of breaker teeth 22 and 23, respectively,which rise from the base of the member I6 and are disposed outwardlybeyond the groove I9. These two series of teethare shown as spaced apartina direction radially of the burner-structure, and-the outer series ofteeth 23 is set in from thecircumference of the base member I6 and thusfrom the side-wall-forming flange I 4. The teeth .22 forming the innerseries thereof are shown as ,of greater height than the teeth 23, whichis preferred in the case of the larger sizes of combustion apparatus;and the same number of teeth are provided in each series thereof andthey arefiodisposed, as shown, as to be in radial alin'ement'witli eachother.

"The upper face of the base portion II contains a series=of downwardlytapering radial slots 24 alternating with the teeth 22 and 23 and theends of whichtermin-ate at upwardly and outwardly inclined walls 24which merge with the upper surface I8 of the-baseportion I1.

The ring member I6 is recessed at its outer periphery as indicated at 26and contains, in its upper face, an upwardly opening groove 21 extendingtangentially of the ring member |6 from the recess 26 to, and through,the inner periphery of this ring member, this groove, which cuts throughcertain of the teeth 22 and 23, serving as a channel through which anigniter flame is projected into the space bounded by ring |6 to ignitethe fuel as hereinafter described.

The structure also comprises an oil-burner assembly at the centralopening in the hearth for projecting radially outwardly and against theinner surface of the ring member l6, atomized oil for the combustionthereof, adjacent the side wall of the combustion chamber as hereinafterdescribed, the flame produced being in the form of a ring.

The oil-burner assembly comprises a neck-ring 28 located in the centralhearth-opening and having an annular external flange 29 underlying thehearth, the ring 28 preferably having an extension ring-section 38.

' The neck-ring 28 is supported at intervals by pipes 32, as for examplefour in number, the lower ends of the pipes 32 extending into openingsin a base-plate 33. Extending upwardly into the pipes 32 are rods 34supported on the floor and slidable in the pipes 32, these several partsbeing held in vertically adjusted position by set-screws 35 on the plate33 which extend through openings in the pipes 32 and bear at their innerends against the rods 34.

The construction shown also comprises a vertically disposed electricmotor 36 supported on a hollow member 31 arranged concentric with theopening in the neck ring 28, the member 31 being supported on the neckring 28.

The upper end of the member 31 is formed of a hollow generallyfrusto-conically shaped portion 43 the open upper extremity of which, issurrounded by a ring 44 located concentrically within the neck ring 28in spaced relation to both the portion 43 and neck ring 28.

Supported to extend downwardly into the upper end of the opening in theneck ring 28 but in spaced relation thereto throughout its circumferenceas shown, isa ring 46 the upper surface of which is so shaped as topresent the annular upwardly tapering surface represented at 41.

Thearmature shaft of the motor 36 is represented at 48 and extendscentrally upwardly through the portion 43 of member 31 to an elevationabove the neck ring 28.

Secured to the upper end of the shaft 48 are air-forcing andair-distributing means of any desirable construction shown as comprisingan inverted shallow, rotatable pan-like member 51 secured to the shaft48, the rim 58 of the member 51 extending downwardly into the opening inthe ring 46. The member 51 contains a series of openings 59 certain ofwhich register with pipes 50 through which the oil, in the operation ofthe motor 36, discharges, the pipes 58 being shown as projectingoutwardly a slight distance through these openings, these means also comprising air-forcing means (not shown) for discharging air outwardlythrough the openings 58. In the operation of the burner structure oilsupplied to the air-forcing and air-distributing means dischargesthrough the tubes 50 and air flows upwardly through the member 43 andthence discharges outwardly as a blast through the openings 59 in thepan member 51, the oil and air so discharging impinging against thehearth ring l6.

The burner assembly is mounted in the furnace at such an elevation thatthe oil discharging from the pipes 50 impinges against the hearth ringI6 substantially in the plane of the base portions of the inner row ofteeth 22, viz., in the plane of the upwardly flaring walls of the slots24.

The installation shown also comprises means for supplying an igniterflame to the hearth through the groove 21, these means which are of theflare-jet type comprising a pilot burner H producing a constant flameand a flare-jet burner 12 both shown as formed of vertically disposedpipes closed at their upper ends and located in the recess 26. Theflare-jet burner 12 is located at the outer end of the groove 21 andcontains an outlet 13 so disposed as shown that the flame,

produced by ignition of the gas discharging therefrom, travels throughthe groove 21 from its outer end, into and through, its inner end to theslgace within the hearth adjacent the oil trough The pilot burner 1| islocated to one side of the groove 21 between the flare-jet burner 12 andthe inner end of the groove 21 and contains a gas-outlet 14 so disposed,as shown, that the flame produced by the gas issuing therefrom extendsinto the groove 21 crosswise thereof, intersecting the stream of gasissuing from the flare jet burner 12 when the latter is opened to thegas supply as hereinafter described, and impinging against the oppositeside wall of the groove 21.

The means shown for controlling the supplying of gas to the burners 1|and 12 may be of any desirable construction such as is commonly in useand preferably of the type operating automatically in the starting ofthe main burner to supply gas to the flare jet burner only during, andfor a few seconds after, the main-burner-starting operation; the meansshown comprising a magnetic gas control assembly formed of a casing 15surmounted by a head 18 containing a passage 11 into which the pipe 18for supplying gas to the burners 1| and 12 opens, the passage 11communicating, under the control of a needle valve 19, with a passageconnected by a pipe 8| with the pilot-burner pipe 1|. The passage 11,which is reduced at its lower end, contains an opening 82 at which itcommunicates with a pipe 83 leading to the flare-jet-burner pipe 12.Interposed between the inlet pipe 18 and the outlet opening 82 is avalve 84 shown as in the form of a ball on the upper end of a stem 85pivotally connected at its lower end to the vertically movable core 86of a solenoid 81 in the casing 15, the coil of which is represented at88. In accordance with common practice the coil 88 is assembled withsuitable electrically controlled devices (not shown), for energizing thecoil to raise the core 86 and unseat the valve 84 and thus permit gas toflow to the flare-jet burner 12 during the burnerstarting periods toignite the atomized fuel and air-mixture discharged to the rim of thehearth as above described.

In the starting of the burner the oil discharging to the hearth ashereinafter described is ignited by the gas-flame produced by theignition means, the groove 21 being so positioned as shown that theigniter flame is projected into the combustion chamber ID in thedirection of rotation of the oil and air delivering means described,viz.,

in the direction of the arrow in Fig. 3.

As a premise to a description of the particular manner in which theburner functions in connection with the hearth construction shown, itmay be statedthat the oil discharging from the pipes 50 is substantiallyuniformly distributed in a circular substantially horizontalsheet aroundthe main burner, impinging against the hearth ring in the plane of thebase portions of the inner row of teeth 22 as above stated, these teethas also the vertical rear side Wall of the oil groove I9 becoming veryhot in the continued operation of the burner and thus thoroughlyvaporizing the oil.

The air, however, in discharging from the burner through the openings 59spreads vertically to a slight degree, portions of the blast forciblyimpinging against the teeth 22 and passing through the spacestherebetween and other portions thereof sweeping downwardly along theupper surface of the hearth below the plane of the oil stream. The lowerportion of the air stream strikes the wall 2| thereby causing the air tobe deflected upwardly against the faces of the teeth 22, most of the airpassing by, without entering, the oil groove I9 thereby causing adeficiency of oxygen in this groove so that the oil vapors therein arenot combustible to a. great degree, which prevents maintenance of asteady flame in the oil groove. A large proportion of the air dischargedthrough the openings 59 sweeps over the top of the teeth 22 into thezone above the teeth 22 and 23 and represented generally at 89.

A part of the air which passes between the teeth 2 2'- as stated enterszones represented generally at 90' and 9| and probably most of the oilvaporized in front of the teeth enters these zones and inasmuch as theamount of oil vapor which passes between the fingers into the zones 90and 9| is far in'excess of the amount that can be consumed by the airwhich enters these zones with the oil vapor, only partial combustion ofthe oil vapor takes place in zones 98 and 9|. As will be understood theair and oil vapor passing through the radial spaces between the teethexpand with resultant decrease in velocity and swirl spirally in thespaces between the teeth 22 and 23 and also the spaces behind the teeth23 which promotes thorough intermixture of the oil vapor and the air.The velocity of the oil vapor and air entering zones 90 and 9! decreasesto such an extent that stable combustion can be established in thesezones; however, the partially consumed gases in traveling from the zonesof incomplete combustion adjacent the teeth 22 and 23 into zone 89become mixed with the air flowing into this zone as above stated forminga completely combustible mixture which thereupon burns in this zone.

The feature of forming the hearth ring IS with the recess 20 affordingthe wall surface 2| is of advantage inasmuch as the height of suchsurface is predetermined and fixed in the manufacture of the hearthring, and reliance is not required to be placed on the workmaninstalling the apparatus in a furnace, to produce the desired height ofwall, as in the case of these structures wherein the elevation of thelower exposed edge of such 7 wall is determined by the height to whichthe 16 would be two inches from the outside curved surface I 6 of thesection and 7 inches from the center about which inner and outerarcsurfaces of the section are described and the distance between thepoints Hi -Hi is 2 pi or 6.28 inches less the necessary clearance forcement joints between adjacent sections, when it is desired to cementthe joints between adjacent sections. The inclination of the surfaces I6is such that in a hearth of I8 diameter adjacent tile will fit togetherat the surfaces lfi'" as shown in Fig. 5, and by using an additional oneof the sections to form a hearth of 20 diameter adjacent tile will fittogether at the surfaces l6 as shown in Fig. 6. This same feature ofproviding the hearth sections with double inclined ends as abovedescribed also applies to smaller and larger hearth sizes than thoseabove referred to, as for example hearths 14" to 16 or 22 to 26 indiameter, in which cases the radius differs accordingly so that one sizeof hearth section will serve for hearths of 14" to 16" diameter andanother size for hearths of 22" to 26" diameter.

While we have illustrated and described a particular constructionembodying our invention we do not wish to be understood as int-ending tolimit it thereto as the same may be variously modified and alteredwithout departing from the spirit of the invention.

What we claim as new, and desire to secure by Letters Patent, is:

1. In oil combustion apparatus, the combination of a combustion chamberhaving a hearth with a raised portion adjacent its periphery and havinga surrounding wall structure, and means at the center of said hearth andextending above the latter for projecting finely divided oil and airagainst the raised portion of said hearth, said raised portioncomprising an annular series of breaker teeth spaced from thesurrounding wall structure to: provide-a combustion space outwardlybeyond said teeth with which the spaces between the teeth communicatethe side walls of the spaces between the teeth at the bottom portionsthereof converging downwardly to produce substantially V-shaped spacesand said means being so positioned as to discharge the oil against thebases of said teeth and into said substantially V-shaped spaces.

2. In oil combustion apparatus, the combination of a combustion chamberhaving a hearth with a raised portion adjacent its periphery and havinga surrounding wall structure, and means at the center of the hearth andextending above the latter for projecting finely divided oil and airagainst said raised portion, said raised portion comprising inner andouter rows of breaker teeth the rows of teeth being spaced apart and theteeth of the outer row spaced from the surrounding wall structure toprovide a combustion space between the outer row of teeth and said wallstructure and with which the spaces between the teeth of said outer rowcommunicate, the teeth of said rows being in substantial radialalinement.

3. In oil combustion apparatus, the combination of a combustion chamberhaving a hearth with a raised portion adjacent its periphery and havinga surrounding wall structure, and means at the center of the hearth andextending above the latter for projecting finely divided oil and airagainst said raisedportion, said raised portion comprising inner andouter rows of breaker teeth the rows of teeth being spaced apart and theteeth of the outer row spaced from the surrounding wall structure toprovide a combustion space between the outer row of teeth and said Wallstructure and with which the spaces between the teeth of said outer rowcommunicate.

4. In oil combustion apparatus, the combination of a combustion chamberhaving a hearth with a raised portion adjacent its periphery and havinga surrounding wall structure, and means at the center of the hearth andextending above the latter for projecting finely divided oil and airagainst said raised portion, said raised portion comprising inner andouter rows of breaker teeth the rows of teeth being spaced apart and theteeth of the outer row spaced from the surrounding wall structure toprovide a combustion space between the outer row of teeth and said wallstructure and with which the spaces between the teeth of said outer rowcommunicate, the teeth of the inner row extending above the teeth of theouter row.

5. A hearth ring comprising sections of arcuate form, those portions ofthe end surfaces of the sections adjacent the outer side of the hearthring being on radii of the circle including the outer edge of thesection and the portions adjacent the inner side being chamfered toextend at an angle to said portions of the end surfaces which areadjacent the outer side of the hearth ring.

6. In combustion apparatus, the combination of a furnace structure, aburner assembly located at the bottom of said structure substantiallycentrally thereof and a hearth for the bottom of said furnace structurecomprising a base member having a central opening in which the burnerassembly is positioned, said base member having an endless upwardlyextending flange adjacent its outer periphery, the inner surface of saidflange being circular and substantially concentric with the opening insaid base member, said base member with its flange filling the spacebetween said burner assembly and the side wall of the furnace structureand conforming to the latter, a hearth ring formed of separate end toend disposed sections placed in superposed position on said base memberand against the inner side of said flange, and a ring on said basemember completely spanning the space between said hearth ring and saidburner assembly.

7. In combustion apparatus, the combination of a furnace structurecomprising an upwardly extending wall, a hearth therein having a raisedportion adjacent its periphery, means at the center of said hearth andextending above the latter for projecting air and finely divided oillaterally, said raised portion having an angularly disposed channelopening through the inner face of said raised portion, and ignitionmeans the flame from which extends forwardly along said channel, saidlast-named means being located between said raised portion and the wallof said furnace structure and subjected to the heat of burning gases inthe furnace outwardly beyond the inner face of said raised portion.

8. In combustion apparatus, the combination of a furnace structurecomprising an upwardly extending wall, a hearth therein having a raisedportion adjacent its periphery, the upper portion of the outer face ofsaid raised portion being spaced from the wall of said furnacestructure, means at the center of said hearth and extending above thelatter for projecting air and finely divided oil laterally, said raisedportion having an angularly disposed channel opening through a side ofsaid raised portion facing said means,

and ignition means the flame from which extends inwardly along saidchannel, said lastnamed means being located between the upper portion ofthe outer face of said raised portion andthe wall of said furnacestructure.

9. In oil combustion apparatus, the combination of a combustion chamberhaving a hearth and presenting an impact wall, rotary means at thecenter of said hearth and extending above said hearth for projecting airand finely divided oil laterally against said impact wall, the raisedportion of said hearth having an angularly disposed channel opening intothe combustion chamber through said impact wall, and ignition means theflame from which extends inwardly along said channel, said channel beingso disposed that the ignition flame discharges into said combustionchamber generally in thedirection of rotation of said first-named means.

10. In oil combustion apparatus, the combina-- tion of a combustionchamber having a hearth with a raised portion adjacent its peripherypresenting upwardly extending teeth spaced apart around the combustionchamber, means at the center of said hearth and extending above thelatter for projecting air and finely divided oil laterally, the raisedportion of said hearth having an angularly disposed channel intersectingcertain of said teeth and opening into the combustion chamber, andignition means the flame from which extends inwardly along said channel,the radial spaces between the teeth intersected by said channel beingsubstantially of the same width as the spaces between the'remainder ofsaid teeth to insure uniformity of performance around the hearth.

11. In oil combustion apparatus, the combination of a combustion chamberhaving a hearth and a surrounding wall structure, said hearth having araised portion adjacent its periphery and comprising a base portion andinner and outer rows of teeth rising therefrom, the rows of teeth beingspaced apart and the teeth of the outer row spaced from the surroundingwall structure to provide a combustion space between the outer row ofteeth and said wall structure and with which the spaces between theteeth of said outer row communicate, the spaces between the teeth ofeach row thereof extending below the upper surface of said base portionand said upper surface containing radial grooves alining, andcommunicating, with said spaces, and means ,at the center of said hearthand extending above the latter for projecting air and finely divided oillaterally against said raised portion.

12. In combustion apparatus, the combination of a furnace structure, aburner assembly located at the bottom of said structure substantiallycentrally thereof and a. hearth for the bottom of said furnace structurecomprising a base member having a central opening in which the burnerassembly is positioned, said base member having an endless upwardlyextending flange adjacent its outer periphery, in sealed relationshipthereto, and a hearth ring on said base member within the confines ofsaid flange, said hearth ring, at

assembly is positioned, said base member having an endless upwardlyextending flange adjacent its outer periphery, the inner surface of saidflange being circular and substantially concentric with the opening insaid base member, said base member with its flange filling the spacebetween said burner assembly and the side wall of the furnace structureand conforming to the latter, and a hearth ring placed in superposedposition on said base member and against the inner side of said flange,the upper portion of said hearth ring being spaced from said fiange andforming, with said flange, walls of a combustion space, said flangeextending above the top of said hearth ring.

14. A hearth element formed of a base portion and inner and outer rowsof teeth rising therefrom, the rows of teeth being spaced apart with thespaces between the teeth of each row opening to the inner and outerfaces of the teeth and the outer side of said base portion extendingoutwardly beyond the outer faces of the outer row of teeth.

15. In oil combustion apparatus, the combination of a combustion chamberhaving a hearth with a raised portion adjacent its periphery, and meansat the center of the hearth and extending above the latter forprojecting finely divided oil and air against said raised portion, saidraised portion comprising inner and outer rows of breaker teeth the rowsof teeth being spaced apart, and the teeth of the inner row thereofextending above the teeth of the outer row.

16. In oil combustion apparatus, the combination of a combustion chamberhaving a hearth with a raised portion adjacent its periphery and havinga surrounding wall structure, and means at the center of the hearth andextending above the latter for projecting finely divided oil and airagainst said raised portion, said raised portion comprising a baseportion and inner and outer rows of breaker teeth rising from said baseportion, the teeth of said rows being in substantial radial alinement,the rows of teeth being spaced apart and the teeth of the outer rowspaced from the surrounding wall structure to provide a combustion spacebetween the outer row of teeth and said wall structure and with whichthe spaces between the teeth of said outer row communicate, and theupper surface of said base member having substantially radial groovesopen at their inner ends and extending from the inner faces of the teethof the inner row beyond the corresponding faces of the teeth of theouter row and located at the bottoms of the spaces between adjacentteeth of both of said rows.

1'7. A hearth element formed of a base portion 7 and inner and outerrows of teeth rising therefrom, the rows of teeth being spaced apartwith the spaces between the teeth of each row opening to the inner andouter faces of the teeth and the outer side of said base portionextending outwardly beyond the outer faces of the outer row of teeth,said element having a portion presenting a substantially verticalinwardly facing curved wall surface located between the innermostsurface of said base portion and the inner surfaces of the inner row ofteeth and extending to an elevation below the upper ends of said lastreferred to teeth.

18. In oil combustion apparatus, the combi nation of a combustionchamber having a hearth with a raised portion adjacent its periphery andhaving a surrounding Wall structure, and means at the center of thehearth and extending above the latter for projecting finely divided oiland air against said raised portion, said raised portion comprisinginner and outer rows of breaker teeth the rows of teeth being spacedapart and the teeth of the outer row spaced from the surrounding wallstructure to provide a combustion space between the outer row of teethand said Wall structure and with which the spaces between the teeth ofsaid outer row communicate, the teeth of said rows being in substantialradial alinement and the side Walls of the spaces between the teeth ofthe inner row at the bottoms thereof converging downwardly to producesubstantially V-shaped spaces, said means being so positioned as todischarge the oil against the bases of said teeth and into saidsubstantially V-shaped spaces.

19. In oil combustion apparatus, the combination of a combustion chamberhaving a hearth with a raised portion adjacent its periphery and havinga surrounding wall structure, and means at the center of the hearth andextending above the latter for projecting finely divided oil and airagainst said raised portion, said raised portion comprising inner andouter rows of breaker teeth the rows of teeth being spaced apart and theteeth of the outer row spaced from the surrounding wall structure toprovide a combustion space between the outer row of teeth and said wallstructure and with which the spaces between the teeth of said outer rowcommunicate, the teeth of said rows being in substantial radialalinement, and the side walls of the spaces between the teeth of each ofsaid rows at the bottoms thereof converging downwardly to producesubstantially V- shaped spaces, said means being so positioned as todischarge the oil against the bases of said teeth and into saidsubstantially V-shaped spaces.

20. In oil combustion apparatus, the combination of a combustion chamberhaving a hearth with a raised portion adjacent its periphery, means atthe center of said hearth and extending above the latter for projectingfinely divided oil and air laterally, the raised portion of said hearthhaving a tangentially disposed upwardly opening channel opening into thecombustion chamber, said hearth having a recess at its outer peripherywhich recess opens into the outer end of said channel, and ignitionmeans in said recess for directing an ignition flame inwardly along saidchannel, for the purpose set forth.

OSCAR C. SCHROEDER. STANLEY PERRY.

